my_name  =  'Zed A. Shaw' 
my_age  =  35  # not a lie 
my_height  =  74  # inches 
my_weight  =  180  # lbs 
my_eyes  =  'Blue' 
my_teeth  =  'White' 
my_hair  =  'Brown' 

puts  "Let's talk about %s."  %  my_name 
puts  "He's %d inches tall."  %  my_height 
puts  "He's %d pounds heavy."  %  my_weight 
puts  "Actually that's not too heavy." 
puts  "He's got %s eyes and %s hair."  %  [ my_eyes ,  my_hair ] 
puts  "His teeth are usually %s depending on the coffee."  %  my_teeth 

# this line is tricky, try to get it exactly right 
puts  "If I add %d, %d, and %d I get %d."  %  [ my_age ,  my_height ,  my_weight ,  my_age  +  my_height  +  my_weight ]


#在ruby中，%后接各种字符代表不同的含义， 
# %{string}用来创建一个双括号的字符串
# %s用于生成一个符号对象
# %r{string}用于创建一个正则表达式字面值
# %x{string}用于执行string所代表的命令

